Resilient sheet



May 16, 1939. L A. DUNAJEFF RESILIENT SHEET Filad lay 14, 1937 lE'O/V/DA. DUNA J'EFF INVENTOR F fla'am/ ATTORNEY Patented May 16, 1939 PATENTorrlcs RESILIENT SHEET Leonid A. Dunajeif, New York, N. Y., assignor toCommercial Ingredients Corporation, New York,

N. Y., as trustee Application May 14, 1937, Serial No. 142,630 '1Claims. (01. 29-180) My invention relates to resilient sheets and hasparticular reference to perforated and corrugated sheets made of aresilient material.

The object of my invention is to provide a sheet 6 having highresiliency and substantial elongation in all directions combined withsuflicient strength to withstand transverse loads, so that it can beused as a material for making seats and backs of chairs and similarfurniture or as a foundation for 10 upholstering in place of ordinarysprings. For this purpose I use metal sheets of high resiliency, such ascarbon or alloy steel, bronze etc., perforated so as to produce amesh-like structure, the perforations resulting in the formation of aplurality of interconnecting bridges, and these bridges are thencorrugated so as to form them into stretchable springs. The sheet, whenperforated and formed, can-be heat treated to increase its resiliency ifmade of carbon steel. With .9 other metals and alloys the resiliency canbe imparted by the cold working of the metal. My sheet, in order to beexpansive or stretchable in all directions, must have corrugated bridgesseparated by perforations between elements which are connected by thebridges, and the perforations must extend across the bridges. It isevident that any longitudinal corrugations. will not make the bridgesexpansive lengthwise. The corrugations, however, need not extend atright angles to the axis of the bridge. They may extend even at anangle, provided that they cross the bridge, 1. e., begin and end in theperforations, so as to render the bridge expansive lengthwise. In thefollowing description therefore the term I transverse" or substantiallytransverse" horrugations will include all such corrugations as cross thebridges and end in the perforations or are interrupted by perforations.

Another object of my invention is to provide a 40 resilient sheet whichcan be prepared of large sheets of metal as described above, thesesheets being then cut and trimmed to suit various practicalapplications.

Another object of my invention is to provide a I resilient sheet formedwith a plurality of corrugated spring-like portions extending in variousdirections, the corrugations projecting to one side of the sheet,leaving the other side smooth so as to provide a smooth front side forthe chair seats 50 and backs, or for other similar applications wherethe surface must be smooth. The smooth surface may be then covered bysomeflexible inelastic protective material.

Another object of my invention is to provide a method of makingresilient sheets, consisting in perforating a sheet so as to form aplurality of interconnected bridges, and corrugating the bridges intospring-like resilient members.

My invention is more fully explained in the accompanying specificationand drawing in which:

Fig. 1 is a front view of my resilient sheet.

Fig. 2 is a sectional view of the same.

Fig. 3 is a front view of a modified resilient sheet.

Fig. 4 is a sectional view of the same.

Fig. 5 is a front view of another modification.

Fig. 6 is a sectional view of the same.

Fig. 7 is a front view of a resilient sheet made to form a chair seat.

Fig. 8 is a sectional view of the same.

Fig. 9 is a diagrammatic view of my resilient sheet deflected under aload.

My resilient sheet consists of a sheet of metal I,

.preferably carbon steel which can be heat treated to a spring temper,or an alloy which can be made resilient by cold rolling and stamping orforming operations. It is provided with a plurality of perforations 2,the material between the perforations forming bridges 3 extending atright angles to each other. Portions 4 of the sheet of metalinterconnecting the bridges may be provided with holes 5 which may beused for attaching the sheet to supporting frames or for attachingcovering and upholstering materials to the sheet. The bridges are foldedor corrugated as shown so that every so bridge forms a spring which canexpand under load, returning to the original shape when the load isremoved.

The corrugations act as small individual springs imparting a certainelasticity to the whole sheet in all directions. The result is that thesheet defiects under a load as if made of a very elastic substance, asshown in Fig. 9 where an elastic sheet 1 is fastened to a frame 8 and isdeflected by a load 9 at different points. The curve of de- 0 flection,of course, will vary considerably for an irregular distribution of loadas every individual spring will become deflected in accordance with itsload. My sheet therefore can replace mattress and bed foundations madeof individual helical springs at a considerably reduced cost and withincreased reliability. The use of a single integral sheet eliminates alarge number of joints necessary with a helical spring assembly therebyalso eliminating points of friction and wear, these points of frictionbeing often a cause of annoying squeaks. The sheets can be made instandard sizes and trimmed to suit particular applications, the holes 5being then used for attaching the sheet to its supporting frame and alsofor attaching fabric and covers. The front side of the sheet is madesmooth by keeping the corrugations 6 below its front surface as shown inFig. 1.

A modified structure is shown in Figs. 3 and 4' with hexagonalperforations III which may be elongated in one direction so as to obtaina greater resiliency in one direction.

Another modification is shown in Figs. 5 and 6. Here holes II areprovided at the points of inter-. section of corrugations l2, the sheetbeing of a somewhat greater rigidity and strength than the sheet shownin Figs. 3 and4. It has a smoother and more uniform surface suitable forcertain applications where a flat metal surface may be required withoutany covering by a fabric, as in metal chairs, for instance.

Another modification is shown in Figs. 7 and 8 depicting a sheet l3 madeas a seat for a chair and provided with holes ll at its edges forfastening these edges to the frame of the chair. The perforations l5 aremade of different sizes in order to adjust the resiliency .of thecorrugations 6 and, partly, for ornamental purposes, if the sheet isleft uncovered by any upholstering.

My resilient sheets are especially suitable for ofllce and outdoorfurniture where it is desired to have all-metal furniture withsufficiently soft or resilient seats and backs; also for hospitals etc.where the furniture must be sanitary and can be washed and sterilized.

I claim as my invention:

1. An expansive sheet having a plurality of portions connected bybridges with perforations between the bridges, every portion beingconnected by the bridges with at least three other portions, the bridgeshaving corrugations directionally extending in a. substantiallytransverse direction, the corrugations being interrupted by theperforations.

2. A resiliently expansive sheet formed integrally with portionsconnected by bridges with perforations between the bridges, the bridgeshaving substantially transverse corrugations for rendering themlongitudinally expansive, the cormgations being interrupted by saidperforationsg every portion being connected by bridges with at 5 leastthree other portions.

3. A resiliently expansive sheet formed inte-i grally with portionsconnected by bridges with perforations between the bridges, the bridgeshaving substantially transverse corrugations for 1D rendering themlongitudinally expansive, the corrugations being interrupted by saidperforations, the portions being provided with supplementaryperforations.

4. A resiliently expansive sheet made of perfo- 15 rated sheet material,the perforations being distributed so as to leave a pattern of portionsinterconnected upon their outsides by bridges, the bridges being foldedin substantially transverse directions, the ridges of the folds beinginterrupted by the perforations.

5. A sheet made laterally expansive by folding it into a plurality ofgroups of corrugations forming rows, the corrugations of one group ofrows extending in generally parallel directions but in- 25 tersectingthe corrugations of the other groups of rows, the corrugations at thepoints of intersection being interrupted by perforations.

6. "A sheet made resiliently expansive indifferent directions by foldingit into a plurality of 30 groups of corrugations, the corrugations ofone group directionally intersecting the corrugations of other groups,the corrugations at the points of intersection being interrupted byperforations.

'7. A resiliently expansive perforated sheet hav-

